The present invention relates to a method of reducing the peak load of energy supply network systems to which a number of consumer units, each of which has several consumers, are connected, whereby the power consumption of the consumer units can be limited to a predetermined limiting value. The present invention also relates to an apparatus for limiting the power consumption of a consumer unit that includes several consumers and is fed from an energy supply connection.
Energy supply network systems, to which a number of consumer units, each having several consumers, are connected, have to be structured regarding their capacities in such a way that they can easily meet the peak demand of the consumer units if many of the consumers are switched on simultaneously. The consumer units can be business enterprises, public network systems, households etc., with each having several consumers, e.g. electrical machines, heating devices, lighting devices etc. The total energy consumption of the consumer units fluctuates under statistical factors, whereby, however considerable power loads are the case if, e.g. on cold days, when many heating devices are in operation, additionally cooking devices are in operation after a television show, warm water is used for showers etc.
DE 34 26 542 A1 discloses a method or a means for the load limitation in energy supply network systems, whereby a means is connected in series to the energy consumption counters linked to each household, which means contains an audiofrequency-ripple control receiver, a load control unit and a power switch. The means is controlled by a central unit in such a way that in case the complete network system load approaches the critical point of the electric supply enterprise, the load limiter is activated by the audiofrequency-ripple control receiver. This allows every single household the consumption of a defined maximum power only. Hence, the household is urged to determine the power input of its consumers in such a way that the maximum power as a limiting value is not surpassed. If this does not occur, the household will get switched off completely by the central unit. Although the described means can limit the peak load of electric network systems, in reality such means did not gain acceptance since households, as experiences has shown, do not reduce their electric consumption if requested to do so. A complete switch off of a household is totally unacceptable for customers and it can lead to dangerous or at least cost-effective side effects.
It is therefore an object of the present invention to provide a method of the aforementioned general type whereby the peak load of the energy supply network systems can be efficiently reduced in a manner that is acceptable for the customers, especially individual households.